1. Field
Example embodiments relate to an optical connector and a stack module including the same, and, more particularly, to an optical module for directly transferring optical signals without any optical transfer unit and a stack module for performing direct data communication with vertically neighboring modules using the optical connector.
2. Description of the Related Art
In an electronic system having integrated circuit devices, electrical connections between chips, between circuit boards and between modules is usually structured by a conductive metal wiring. However, the electrical connections via the metal wiring have caused problems according to the recent technical trends of high speed and high performance of electronic systems. For example, the metal wiring has caused electric-based faults such as electromagnetic interference and high electrical resistance and device faults, such as low operation efficiency and an interrupt for high degrees of integration. Those problems caused by high speed and high performance of recent electronic systems have become more serious as multimedia-based mobile devices, such as smart phones and tablet PCs and digital interactive TV have become more widely spread.
An optical communication device has been widely used for transferring large-sized data at high speed.
A conventional optical communication device includes a light emitting diode electrically connected with a first data source, a photo detector electrically connected with a second data source, and a photo transfer unit interposed between the light emitting diode and the photo detector as an optical path. The optical signal generated from the light emitting diode passes through the photo transfer unit toward the photo detector. The light emitting diode and the photo detector may be located independently from each other due to the photo transfer unit.
The optical transfer unit is usually built in a communication package or an electronic system including an optical module. Otherwise, the optical transfer unit is additionally provided separately from the communication package or the electronic system. Particularly, when the light emitting diode and the photo diode are spaced apart far away from each other and it is difficult to provide the additional optical transfer unit, a flexible optical cable may be used for transferring the optical signal.
However, the conventional optical cable has disadvantages in that it is difficult to align the optical cable with the center of the photo diode and the volume of the optical cable could be a barrier to a small size communication package. In general, the center of the optical cable is aligned with the light source of the photo diode with an extremely small alignment margin on the order of micrometers and, thus, an additional alignment tool is generally used for aligning the optical cable with the photo diode, which increases manufacturing cost of the communication package including the optical cable and the photo diode and of the electronic system including the communication package.
In addition, when the first data source and the second data source are vertically stacked in the optical communication module, the optical transfer unit usually causes various limitations for modification of the optical communication module. The electronic system is usually manufactured by individually assembling a number of semiconductor packages, and, thus, the optical transfer unit cannot be formed into the semiconductor package together in one body. Further, when the flexible optical cable is adopted for the optical transfer unit, the optical cable is installed away from the printed circuit board (PCB) and, thus, the electronic system may not have a small size due to the additional optical cable.